Lubrication system for internal



March 14, 1939. M, J. scHNK JUBRICATION SYSTEM FOR INTERNAL COMBUSTIONENGINES 4 Sheets-Sheet 1 Original Filed Oct. 17, 1929 .www .EUNIS-juill/H j March 14, 1939. M. J, s'cHENK R- 21,031

LUBRIGATION'SYSTEM FOR INTERNAL COMBUSTI'ON ENGINES Original Filed O ct.1'7, 1929 v 4 Sheets-Sheet 2 .ffii f f. fy f.

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March 14, 1939.'

M. J. vsel-Erm l LUBRICATION SYSTEM FR INTERNAL COMBUSTION ENGINES 4Sheets-Sheet original Filed oct. 17. w29

March 14, 1939. M. .J scHENK R 21,031

LUBRICAT'ION'SYSTEM FOR INTERNAL COMBUSTION ENGINES Original Filed Oct.17, 1929 4 Sheets-Sheet 4 rIl `Reissued Mar. 14, 1939 PATENT OFFICELUBRICATION SYSTEM FR INTERNAL COMBUSTION ENGINES Martin J. Schenk,Chicago, Ill., assignor, by direct and mesne assignments, ofthirty-three and one-third per cent to It. Picard, Chicago,

Ill.

Original No. 1,815,868, dated July 21, 1931, Serial No. 400,383, October17, 1929. Application for reissue December 27, 1938, Serial No. 248,009

22 Claims.

come into such wide commercial and militaryv use.

Engines of this type have'been generally accepted as the most practicaltype of engine for aeroplanes, and their acceptance has been due to thefact that they vfurnish a maximum of power per pound of engine weight,their iightness being dueto the lesser amount of metal needed in thecylinders than in enginesof the water cooled type, and to the fact thatno cooling radiators and fluid are necessary. However, certain drawbacksto the use of radial engines have been encountered and chief among theseare the.

difiiculty in' properly lubricating the entire valve gear and properlycoolingthe valves.

These drawbacks have been such as to necessitate the disassembly ofthe'entire valve gear after every'ilfteen hours of iiying time in orderto thoroughly lubricate the same and have further made it necessary tocompletely overhaul 25 zthe engine after 200 hours oi.' use-in order togrind the valves, and replace any such -valves as may have become burnedor warped. It has been impossible, up to .the present time, to carry outany long sustained iiights Without rigging up an auxiliary lubricatingdevice for. the valves which can be controlled from the cockpit o f theplane, or lubricating the `valves with a manually operated pressuregum-which means that it is necessary for the flight mechanic to climbout 35 of `the cockpit of the plane to the engine and attach the gun toeach of the lubricating nipples provided on the rocker arms'ofv thevalve gear. l

These expedients have proved both inefiicient and dangerous, as it isimpossible to thoroughly 40 lubricate all parts of the valve gear bythese methods.

The object of my invention is to overcome the vabove-mentioned.troublesand to? thoroughly lubricate the valve gear and cool the valves auto-.matically.

1- Further my improvementis made an integral i part yof the lubricationsystem now Vembodied in Ir-the type of eng-ine referred, to and isfsoarranged as to be applicable to'engines ,nowvin service with f but fewchanges of fparts.'

The above object is attained to the valves in orderI to` cool' thesama-after lbyl forcing oil,v Y under pressure, to all parts of thevalve gear and employed in the usual lubrication system which hasheretofore been conilned `to the crank case of the engine.

A complete understanding oi' my invention may be had by reference to theaccompanying drawings, of which:

Fig. 1 is a face view of an engine embodying my improvement;

Fig. 2 is a vertical section oi' the same engine;

Fig. 3 is a vertical section through a cam follower;

Fig. 4 is a section through line L-I of Fig. 3;

Fig. 5 is a section through line 5--5 of Fig. 3;

Fig. 6 is a section through line 6 6 oi Fig. 3;

Fig. 7 is a detail view in section. showing the valve gear for one valveon the cylinder head;

Fig. 8 is a longitudinal section of a valve showing the oil circulatingpassages:

Flg.- v9 is a section through one of the valve' rocker arms;

Fig. 10 is a section through 8; and g Fig. 1l is a section through thevalve adjusting means showing the oil passages therein'.

. Myinvention is illustrated as applied to a nine cylinder, radial,air-cooled engine in which the cra-nk case-is designatedby the numeralI, the cylinders, which are disposed radially` about the crank case,vas2 andthe rocker arm boxes as 3, there being two such boxesto eachcylinder, one for the exhaust valve and one for the intake valve.Inasmuch as the mechanism operating each valve andthe system forlubricating such \mechanism is the` same throughout the engine it willonly-be necessary to describe the mechaune llt-#loef Fig.

' nism as applied to a single valve.

Each box is providedwithan oil tight cover 4 which can be' removed topermit adjustmens to the valves, the remainder of the valve box beingcast integral with the cylinder head. Within each rocker arm box is arocker arm 5 pivoted about a shaft 0.4 so as tooperate `the valve 1lwhich is normally. held in a closed position by springs 0. Eachrockerarm is operated f by means of a hollow push rod 9 having a roundedhead- I0 which is drilled to permit the passage of oil therethrough. Theoil passage in thepush rod communicates with an oil passageV lli in the.rocker arm, whichpassage` alsogfeeds the roller bearing on,l which Ythe`roclrineravrln is.' journaled, and the valve adjusting.l means which.consists of a threaded screw member: I2 havinga hemi- .spher-icalconcavity ,inthe A.lower end thereof. The screw member i 2 is heldinitsadjusted position by means of a .locking nut lian'dfis provided withan annular groove I4 about its median portion which communicates withoil passages within the screw member and with the oil passage II in therocker arm. Between the lower end of the acusting screw I2 and the topof the valve 1 there is provided a friction reducing member I5 having anoil passage therethrough. This anti-friction member is rounded on top toco|ncde with the concavity in tue adjusting screw I2 and is providedwith a plane surface on the bottom for engagement with the stem of thevalve 1.

'Ihe valve 1 has been specially designed to meet the need for a valvewhich can be readily cooled, and to this end is so constructed as topermit the passage of cooling oil therethrough. a 'I'he valve isprovided with an inlet passage I6, a hollow chamber I1 in the head andan outlet passage I3. By reference to Figs. 8, 9 and 10, the details ofthe valve construction are readily apparent.

The main portion of the valve consisting of the stem and head is firstformed, the oil passages I3 and I3 are then drilled in the stem, afterwhich a disc 1a is pressed into the cavity I1, and forms an oil tightjoint with the undercut shoulder on the valve.

The hollow push rod 9 is provided at its lower extremity with ananti-friction member Ia having a rounded end which engages in aconcavity in the top of a cam follower. 'I'he member Ila is also drilledto permit the passage of oil therethrough. The cam follower consists ofupper and lower parts I9 and 23 between which is placed the spring 2|.The upper portion I9 of the cam follower has drilled therein thecylindrical cavity 23. 'I'he lower portion 20 of the cam follower isturned down to form the protuberance 24y which tits into the cavity 23in which is placed the spring 2|. 'Ihe upper part of the cam follower isdrilled to form the oil passages 22 and the lower part is drilled toform the connecting passages 25 and 28. The cam is designated by theletter C and the cam follower and the rest of the valve gear isoperated-through the medium of the roller 21 journaled on a shaft 23which in turn is mounted in a slot in the lower portion of the camfollower. Oil is supplied to the roller by housing 3| which is fixed inthe crank case I and .return of oil tothe crank case.

is restrained against rotation by pin 2 Ia. Through the housing 3| isdrilled a passage 32 for the 'Ihe housing 3| is further provided with ahollow internally threaded pipe connection 33, into which is threaded aconnection 34 communicating with a manifold 35.- Within the connection33 is placed a ball check 36 which is prevented from closing the port tothe oil passages in the cam follower by means of a pin 31. 1

Between the top of the cam follower housing and the bottom of the rockerarm box 3 there is provided a telescoping push rod cover 33, which canreadily be applied to the push rod between the cylinder and the camfollower housing.

From the lowest portion of each rocker arm box a pipe 39 leads to amanifold 4I for returning the oil which has been through the system backto an oil sump 4| from which itis drawn through the strainer 42 and apipe 43. The sump is provided at its lowest extremity with a drain plugthrough which accumulated dirt and water which has entered the systemmay be withdrawn. This manifold 4|I surrounds the crank shaft, the

upper portion lying between the rocker arm xes 3 and the crank shaft,while the lower portion of l the manifold is outside of the boxes 3, sothat each of the boxes 3 is above anadjacent portion of the manifold,whereby the oil is drained by gravity from each of the boxes 3 to themanifold 40 through its pipe 33, see Fig. 1. y

Within the crank case I is shown a pipev 44 (Fig. 2) carrying oil fromthe usual pump (not shown) to the crank shaft. From this pipe 44 is ledanother pipe 45 which feeds oil to the manifold 35.

Having described the various parts of my improved system in detail, Ishall now proceed to describe the operation of the system in itsentirety.

As before stated, the oil under pressure is conveyed under pressure fromthe usual pump to the crank shaft and allied parts through pipe 44 butas this does not form a part of my invention it will be unnecessary todescribe the same. From the pipe 44 the oil is also conveyed to themanifold 35, which is on the outside of the crank case, by means of thepipe 45. From the manifold 35 outlets are provided to each of the camfollower housings 3|, the ball checks 36 being unseated by the oil, seeFig. 3. After the oil has enteredthe housing 3| part of it passesthrough the groove 29 in the lower portion of the cam follower downwardsto lubricate the roller 21, some of the oil leaking out and lubricatingthe face of the cam C. 'Ihe remainder of the oil enters the passages 25and 23 which discharge into the cavities 23. From the cavitiesr 23 theoil passes through passages 22 in the upper portions of the cam followuers, lubricates the friction surfaces between the cam followers and thelower ends |8a of the push rods. 'Ihe oil now flows up through thehollow push rods 9 by means of the passages in' the upper extremities ofthe push rods, the oil passes into and through the passages I| in therocker arms 5 lubricating the friction'surfaces between the upper endsof the push rods and the rocker arms and also the roller bearings inwhich the rocker arms are journaled, from the passages the oil isconveyed through the passages in the valve adjusting screws I2 and fromthence throughthe passage in the anti-friction members I5 between theadjusting screws andthe tops of the valve stems. The oil then passesthrough the intake channels I6 in the valve stems, circulates within thehollow chambers I1 of the valves and cools the same and then ows throughthe passages |3 and is discharged into the valve boxes, therebylubricating the valve stems.

From the valve boxes the oil ows through the drain tubes 39, placed inthe lowest portions ofthe valve boxes, into the manifold 4l and thenceto the oil sump 4| from which it is drawn'through pipe 43by means of ascavenge pump (not shown) and is returned to the oil reservoir in thefuselage of the plane. The return pipe 43 must necessarily beplaced'below the level of the rocker boxes of the lowermost cylinders inorder to prevent 'the flooding of the rocker boxes. Any oil which mayhave found its way into the push rod covers 33 of the top cylinders willdrain by gravity into the crank case by way of the oil passage 32drilled in the cam follower housings and from the crank case to the sumpin the usual manner.

The lower portions of the cam followers are held against the cam bymeans of the spring 2| within the followers, This spring will also causethe upper portions of the cam followers to be held against the lowerends of the push rods, the

arms and nally the opposite ends of the rocker arms against the tops ofthe valve stems. This construction, it will readily be seen, preventsthe leakingof the oil at the points referred to other than thatnecessary to properly lubricate the friction surfaces. 'I'he springs 2|are of the compression type and operate against the force of the springs8 which -hold the valves in their closed positions. 'I'he `force of thesprings 2l is only about six pounds apiece whereas the force' oi thesprings 8 total about 45 pounds when vthe valves are closed and about 70pounds when the valves are held open by the cam and intermediate valvegear so that the action of the spi-ings 2| can in no way interfere withthenormal operation -of the valves.

There is provided in the valve geara certain` amount of play tocompensate for the expansion of the cylinders, push rods and camfollowers, enough play being allowed so that there exists about .01"between the members I5 and the valve stems when the motor is cold andabout .06" when the motor is hot. As can readily be seen, 'this play -isall taken up between the upper and lower portions I9 and 20 of the camfollowers and isapt to form a slight pumping actionwhich would actagainst the force of the oil pump. This reaction against the pump isprevented by the ball check 36 in each of the cam follow'er housings,which, in levent of any back pressure will seat against the ends of thepipes 3l. It

'f is preferable to allow more clearance than above specifled'and toincreaseithe cam lift proportionately so that a greater pumping actionis caused between the upper and lower port-ions of the cam followersthus creating/a greatere pres-y sure to exist in the system/between theball checks and the-outlets in the valve stems'. It is also evident thatthe springs 2| and the oil in the chambersf23 will provide a cushioningeffect on the various parts of the valve gear as the valves areactuated.

From the foregoing `description it is evident that myimprovement willthoroughly and adequately lubricate all parts of the valve gear and coolthe valves so that flights of the longest duration can be safely carriedout without fear of motor failure due to insufficient lubrication andthe life of a motor between overhauls can be lengthened from 200 hoursto 1000 hours of flying time. 'While-I have, in the-foregoingdescription, described my invention in its preferred form, it is evident`that many changes might be made in its construction and operationwithout departing from the scope ofthe invention. e

- Having now described my invention, what I the lubricant delivered tothe joints when the push rod is moved in one direction, withoutbffecting the pressure in the supply. y

2. A lubricating system for internal combustion engines, having valves,a rocker arm for each valve enclosed wit-hin a chamber, a push rod foreach rocker arm, a lubricant supply, and means for delivering lubricantunder pressure to the joints between the rocker arm and push rod and thevalve and rocker arm and from there to its chamber, and means forreturning oil from each chamber back to the supply. I

3. A lubricating system for internal combustion engines having aplurality of radially disposed cylinders surrounding the crank shaft,valves for each cylinder, a rocker arm for each valve, a casing for eachrocker arm, a push rod for each valve, a 'lubricant source, a lubricantsupply means for delivering lubricant under pressure from the lubricantsource to the joints between each push rod and its rocker arm and eachvalve and its rocker arm, and a downwardly extending drain from eachcasing for returning the lubricant back to said source.

4. A lubricating system for internal combustion enginesl having aplurality of radially disposed cylinders surrounding the crank shaft,valves for each cylinder, a rocker arm for each valve enclosed within achamber, a push rod for each rocker arm, a manifold surrounding thecrank shafta source of lubricant supply, means for delivering lubricantunder pressure from said source to said manifold, connections from saidmanifold for delivering lubricant to the joints between each rocker armand its n manifold for delivering lubricant to the joints between eachrocker arm and its push rod and each rocker arm and its valve, a secondmanifold surrounding the crank shaft, a downwardly extending lubricantreturn connection from each rocker arm chamberto said second ymanifoldto drain said chamber by gravity, and-a 'common lubricant connectionfrom the second manifold to the source of lubricant.

6. A lubricating system for internal combustion engines havingreciprocating valves, a rocker arm for each valve,\a bearing for therocker arm, a hollow push rod for the rocker arrn,` means for actuatingthe push rod, a passage for lubricantin the rocker arm communicatingwith the hollow' push rod and the bearing, a second passage forlubricant in the rocker arm communicating with the bearing and the jointbetween the rocker arm and the end of the valve stem, means for causinglubricant to first flow through the push rod and then through the rockerarm to the' joint between the valve stem and rocker arm and other meansfor increasing the pressure of the lubricant in thesystem when the pushrod is moved in one direc tion.

7. A lubricating system for an internal combustion engine valve gearhaving Ia reciprocating valve provided with a stem, a rocker arm foractuating the valve, a bearing inthe rocker arm, a hollow push rod for-actuating the rocker arm, passages for lubricant Within the rocker armcomsy municating with the hollow push rod, means for actuating the pushrod, the bearing and the joint between the valve stem `and rocker arm,there being a chamber in the valve, a passage in the valve stemcommunicating with the passage in the lliv rocker arm at the jointbetween the rocker arm I and stem, there being an outlet passage fromthe chamber in' the valve stem. means for continuously forcing lubricantthrough the said passages and the chamber in the valve for cooling thevalve andlubricating the rocker arm bearing, the joints between therocker arm and push rod and the joint between the'rocker arm and thevalve stem, means for causing lubricant to rst flow through .the pushrod and then through the rocker arm to the joint between the valve stemand rocker arm, and other means for increasing the pressure of thelubricant in the system when the push rod is moved in one direction.l

8. A lubricating system for internal combustion engine valve gear for areciprocating valve,'comprising a rocker arm for opening theyalve, apush rod for actuating the'rocker arm, a cam, a two partfoliower betweenthe cam and push rod, a housing for the follower parts, a relativelylight spring between the follower parts,'a relatively heavy spring formoving the valve to its closedY position, the light spring tending toseparate the follower parts and maintain the valve gear elements inengagement with each other and with k the valve, there being a spacebetween said follower parts when the valve is closed, adjustable meansfor varying thesize of such space, means for feeding lubricant to saidspace, a check valve for preventing the retrograde movement of lubricantfrom said space when the follower parts are moved towards each other,there being lubricant passages from said space to the joints between theY rocker arm and the push rod and the joint between the valve and rockerarm, whereby lubricant is continuously delivered to said joints by thecombined action of the lubricant feeding means and the relative movementof the follower parts.

9. A lubricating system for internal combustion engine valve gear for areciprocating valve, comprising a rocker arm for opening the valve, apush rod for actuating the rocker arm, a cam, a two part followerbetween the cam and push rod, a housing for the follower parts, arelatively light spring between the follower parts, a relatively heavyspring for moving the valve to its closed position, the light springtending to separate the follower parts and maintain the valve gearelements in engagement with each other and with the valve, there being aspace between said follower parts when the valve is closed, adjustablemeans for varying the sizeof such space, means for feeding lubricant tosaid space, a check valve for preventing the retrograde movement oflubricant from said space, there being a continuous lubricant passagefrom said space through the push rod, and the rocker arm to the jointbetween the rocker arm and the valve, said two part follower acting as apump when the push rod is moved in one direction.

A lubricating system for internal combustion engine valve gear for areciprocating valve having a stem and a head, comprising a rocker armfor opening the valve, a push rod for actuating the rocker arm, a cam, atwo part follower between the cam and push rod, a housing for thefollower parts,` a relatively light spring between the follower parts, arelatively heavy spring for moving-the valve to its closed position, thelight spring tending to separate the follower parts and maintain thevalve gear elements in engagement with each other and with the valve,there being a space between said follower parts when the valve isclosed, adjustable means for varying the size of such space, means forfeeding lubricant to said space, a check valve for preventing theretrograde movement `of lubricant from said f space, there being achamber in the Vvalve head, an outlet passage leading-from said chamber,there being continuous lubricant passages from said space `be tween thefollower parts through the push rod, the rocker arm and valve stem tothe chamber in the valve, whereby lubricant is continuously delivered toall of the joints of the valve gear for lubricating said joints andthrough the chamber` in the valve for cooling the valve, said two partfollower acting as a pump when'the push rod ls moved in one direction. Y

ll. A lubricating system for reciprocating V valves of an internalcombustion engine having a stem, a rocker arm for moving the stem, apush rod for actuating the rocker arm, a follower, a cam for actuatingthe followena roller mounted in the follower in'engagement with the cam,a housing for the follower, means for delivering lubricant to thehousing, there being an oil passage for delivering lubricant from thehousing to the roller,` and there also being a continuous lubricantpassage from said housing through a portion of the follower, the pushrod andthe rocker arm to the joint betweenthe rocker arm and the valvestem.

- 12. A lubricating system for internal combustion engine valve gear fora reciprocating valve including a two part follower, a housing for thefollower, means for adjusting the valve gear to -provide a space betweenthe follower parts when the valve is closed, means for supplying oil tothe space between the follower parts, oil connections from said space tothe joints in the valve gear, means for moving one of said parts towardthe other and then actuating the valve, and means for preventing themovement of the oil from between said parts to the oil supply means,whereby said oil is forced through the oil connections to the joints inthe valve gear.`

13. A two part follower for a valve gear lubricating system, a housingfor the follower parts,

means'forgsupplying oil under pressure within the housing between thefollower parts, means for conducting oil from between said followerparts to the jointsof the valve gear, means for actuating the followerparts, and means for preventing they oil from flowing into the supplymeans when the follower parts are moved toward each other, whereby thepressure of the oil in the system between the housing and the joints 15.A lubricating system for internal combus tion engines having a pluralityof radially disposed cylinders surrounding the crank shaft, valves foreach cylinder, there being a separate chamber inclosing each valveactuating mechanism, a follower for actuating each valve mechanism, ahousing inclosing each follower, means for delivering oil under pressureto each follower housing, means for delivering oil from each housing tothe joints of the valve mechanism actuated' thereby, a manifoldsurrounding the crank shaft of the engine, means for conducting the oilby gravity from each valve mechanism chamber to said manifold, and meansfor returning the oil from the manifold to the oil delivery means.

16. A lubricating system for internal combustion engines having aplurality of radially disposed cylinders surrounding the crank shaft,valves for each cylinder, valve actuating mechanism for each valve, eachof said valve actuating mechanisms being enclosed within a casing, meansfor delivering oil under pressure to each valve actuating mechanism, areturn oil manifold surrounding the crank shaft, the upper portion ofsaid manifold lying between the valve mechanism chambers and the crankshaft while the lower portion thereof is beyond the lower valvemechanism chambers, drain pipes extending downwardly from each of saidchambers to the manifold, and means for returning oil from the manifoldto the supply.

17. An automatic valve gear lubricating system for internal combustionengines of the radial type having a centrally arranged crankcase, aplurality of radially disposed air-cooled cylinders surrounding thecrankcase, valves for each cylinder, and valve-actuating mechanism foreach valve including a hollow rocker arm at the outer end of eachcylinder in operative engagement with the valve, a hollow radiallydisposed push rod in operative engagement with the rocker arm, a hollowcam followerI in operative engagement with the push rod, and a guide forthe cam follower, the push rods being located exteriorly of thecylinders in spaced relation to the latter, and the cam follower guidesbeing located in the crankcase at the inner ends of the push rods; saidlubricating system comprising means for supplying oil under pressure,means for conducting said oil to the cam followers through openings inthe side of the cam follower guides, means for conducting said oiloutwardly `through the cam followers to joints of all the push rods androcker arms, oil-tight enclosures for the rocker arms at the outer endsof the cylinders, oil-tight tubes extending between the rocker armenclosures and the cam follower guides, about the push rods in opencommunication with said enclosures, downwardly inclined pipes at theouter ends of the cylinders in communication at their upper ends withthe lower portions of the rocker arm enclosures for draining by gravityfrom the enclosures oil discharged from joints of the valveactuatingmechanisms, a common oil return beneath the crankcase between the twolowermost rocker arm enclosures into which the oil drained through allof said pipes flows, and a pump for causing the oil from said return toflow back to the oil supply means for recirculation.

18. An automatic valve gear lubricating system for internal combustionengines of the radial type having a centrally arranged crankcase, aplurality of radially disposed air-cooled cylinders surrounding thecrankcase, valves for each cylinder, and valve-actuating mechanism foreach valve including a'hollow rocker arm at the outer end of eachcylinder in operative engagement with the valve, a hollow radiallydisposed push rod in operative engagement with the rocker` lation to thelatter, and the cam follower guides being located in the crankcase atthe inner ends of the push rods; said lubricating system comprisingmeans for supplying oil under pressure. means for conducting said oil tothe cam followers through openings in the sides of the cam followerguides, means for conducting said oil outwardly through the camfollowers to joints of all the push rods and rocker arms, oil-tightenclosures for the rocker arms at the outer ends of the cylinders,oil-tight tubes extending between the rocker arm enclosures and the camfollower guides about the push rods in open communication with saidkenclosures, downwardly inclined pipes at the outer ends of the cylindersin communication at their upper ends with the lower portions of therocker arm en closures for draining by gravity from the enclosures oildischarged from joints of the valve- `leading downwardly from the lowerendsA of the push rod tubes into the crankcase, through which ducts theoil discharged from the push rod joints `in the tubes flows by gravityinto the crankcase.

19. An automatic valve gear lubricating system for internal combustionengines of the radial type having a centrally arranged crankcase, aplurality of radially disposed air-cooled cylinders surrounding thecrankcase, valves for each cylinder, and valve-actuating mechanism foreach valve including a hollow rocker arm at the outer end of eachcylinder in operative 'engagement with the valve, a hollow radiallydisposed push rod in operative engagement with the rocker arm, a hollowcam follower in operative engagement with the push rod, and a guide forthe cam follower, the push rods being located exteriorly ofthercylinders in spaced relation to the latter, and

the cam follower guides being located in the crankcase at the inner endsof the push rods,

y said lubricating system comprising means for supplying oil underpressure, means for conducting said oil to the cam followers throughopenings in Ithe sides of the cam follower guides, means for conductingsaid oil outwardly through the cam followers to joints of all the pushrods and rocker arms, oil-tight enclosures for the rocker arms at theouter ends of the cylinders, oil-tight tubes extending between therocker arm enclosures and the cam follower guides about the push rods inopen communication with said enclosures, downwardly inclined pipes atthe ou'ter ends of all the cylinders which are located below the levelof the center of the crankcase, which pipes are in communication attheir upper ends with the lower portions of the rocker arm enclosures ofsaid cylinders for draining by gravity from said enclosures oildischarged from joints of the valve-actuating mechanisms of saidcylinders, a common oil returnvbeneath the crankcase between the twolowermost rocker arm enclosures into which the oil drained through allof said ,pipes flows, and a pump for causing the oil from said return toflow back to the oil supply means for recirculation, the cam followerguides for all the cylinders which are located above the level of thecenter of the crankcase being provided f with ducts leading downwardlyfrom the lower ends ofthe push rod tubes into the crankcase,

` through which ducts oil discharged from the push surrounding thecrankcase, valves for each cylinder, and valve-actuating mechanism foreach valve including a rocker arm, at the outer end of each cylinder inoperative engagement with the valve, a hollow radially disposed push rodin operative engagement with the rocker arm, a hollow cam follower inoperative engagement with the push rod, and a guide for the camfollower, the

push rods being located exteriorly of the cylinders in spaced relationto the latter, and the cam follower guides being located in thecrankcase at the inner ends of the push rods; said lubricating systemcomprising means for supplying oil, means for conducting said oil to thecam followers through openings in the sides of the cam follower guides,means for conducting said oil outwardly through the cam followerstorjoints of all the push rods and rocker arms, oil-tight enclosures forthe rocker arms at the outer ends of the cylinders, oil-tight tubesextending between the rocker arm enclosures and the cam follower guidesabout the push rods, and means for conducting by gravity baci:` to theoil supply means oil discharged from joints of the vaiveactuatingmechanisms of all the cylinders located above the level of the center ofthe crankcase, said last mentioned meansincluding ducts in the camfollower guides for said cylinders, which ducts lead downwardly from thelower ends of the push rod tubes into the crankcase.

21. An automatic valve gear lubricating system for internal combustionengines of the radial type having a centrally arranged crankcase, aplurality of radially disposed air-cooled cylinders surrounding thecrankcase, valves for each cylinder, and valve-actuating mechanism foreach valve including a hollow rocker arm at the outer end of eachcylinder in operative engagement with the valve, a hollow radiallydisposed push rod in operative engagement with the rocker arm, a hollowcam follower in operative engagement with the push rod, and a guide forthe cam' follower,

the push rods being located Yexteriorly of the cylinders in spacedrelation to the latter, and the cam follower guides being located ln thecrankcase at the inner ends of the push rods; said lubricating systemcomprising means for supplying oil under pressure, means for conductingsaid oil to the cam followers through openings in the sides of the camfollower guides, means for conducting said oil outwardly through thecamY followers to joints of all the push rods and rocker arms, oil-tightenclosures for the rocker arms at the outer ends of the cylinders,oil-tight tubes extending between the rocker arm enclosures and the camfollower guides about the push rods in open communication with saidenclosures, downwardly inclined pipes at the outer ends of the.

cylinders in communication at their upper` ends with the lower portionsof the rocker arm enclosures for draining by gravity from the enclosuresoil discharged from joints of the valveactuating mechanisms, a commonoil return beneath the crankcase between the two lowermost rocker armenclosures into which the oil drained through said pipes ows, and a pumpfor causing the oil from said return to flow back to the oil supplymeans for recirculation,A the cam follower guides for all the cylindersYwhich are located above the level of the center of the crankcase beingprovided with ducts leading downwardly from the lower ends of the pushrod'tubes into the crankcase, through which ducts oildischarged from thepush rod joints in the tubes flows by gravity into the crankcase, eachof said cam followers being made in two spring-expanded pumplike partsbetween which the oil entering from the opening in the side of the camfollower guide iiows and is forced intermittently under momentarilyincreased pressure through the outer part of the cam follower into thepush rod by the contraction of said parts incident to the operation ofthe engine.

22. An automatic valve gear lubricating system for internal combustionengines of the radial type having a centrally arranged crankcase, aplurality of radially disposed air-cooled cylinders surrounding thecrankcase, valves for each cylinder, and valve-actuating mechanism foreach valve including a hollow rocker arm at the outer end of eachcylinder in operative engagement with the valve, a hollow radiallydisposed push rod in operative engagement with the rocker arm, a

hollow cam follower in operative engagement with the push rod, and aguidefor the cam follower, the push rods being located exteriorly of thecylinders in spaced relation to the latter, and the cam follower guidesbeing located in the crankcase at the inner ends of the push rods; saidlubricating system comprisingmeans for supplying oil under pressure,means ,for conducting said oil to the cam followers through openings inthe sides of the cam follower guides, means for conducting said oiloutwardly through the cam followers to joints of all the push rods androcker arms, oil-tight enclosures for the rocker arms at the outer endsof the cylinders, oil-tight tubes extending between the rocker armenclosures and the cam follower guides about the Apush rods in opencommunication with said enclosures, and means for conducting by gravityback to the oil supply means oil discharged from joints of thevalve-actuating mechanisms, said last mentioned means including ducts inthe cam follower guides for all the cylinders located above the level ofthe center of the crankcase, which ducts lead downwardly from the lowerends of the push rod traction of said parts incident to the operationof' the engine.

MARTIN J. SCHENK.

